Apparatus for effecting electrical signaling



Nov. .23, 192e. 1,608,252

' G. O. SQUlER ET AL APPARATUS FOR EFFECTING ELECTRICAL ASIGNALING `Filed Jan. 15-, 1924 ATT@ RN EY Patented Nov. ,23, 1926.-

UNITED STATE-s PATENT oFFicE,

GEORGE O. SGI-TIER, THE UNITED STATES ARMY; LOUIS COHEN, WASHINGTON, DISTRICT'OF COLUMBIA; AND JOSEPH '0. MAUBORGNE, OF THE UNITED STATES ARMY.

APPARATUS EOR EFFECTING ELECTRICAL SIGNALING.

Application filed Januar-y 15, 1924. Seria1 No. 686.304.

crease the speed at which such signals may be transmitted and received. Our improvements are applicable to cable telegraphy, vto

@wire telegraphy, and to radio telegraphy.

' ln signaling by our improved apparatus we utilizevariations in amplitude of the cur rentsv employedvto distinguish the dots and dashes constituting the message, whereby the time required to transmit a dash will be the same as that required to transmit a dot.

` Ve may utilize either direct or alternating currents in carrying our invention into eiiect in connection with cables or land wires. `Then a direct current is employed, the dots and dashes are constituted by current pulses of greater or smaller amplitude. For cable telegraphy, if alternating currents are to be used, they are of low frequency, of the order of ten to twenty cycles per second, and suit- -able commutating devices are employed, so that by means of a suitable sending tape each haltcycle may represent a dot or dash or a space. A suitable resistance 'in the alternating circuit is properly controlled to give the `maximum voltage in the `case of a dash,'a smaller voltage in the case of a dot, and a still smaller or no voltage in the case of a space. `For radio telegraphy, either spark signals or continuous waves may be employed suitably controlled to give the desired voltage differences at the receiving station to distinguish the dots from the dashes. For instance, with a spark transmitter greater energy may be transmitted from the antenna in the case ot a dash than in the case ot a dot; in the case of continuous waves the latter may be suitably modulated to represent the desired variations in ampli tude corresponding to thesignal. IVe do not claim ,herein the particular method orA4 apparatus for generating the required signuls at the. transmitting end; it is only necessary that the respective dots and dashes which constitute the signal shall vary in amplitude but not in time, this variation being impressed either upon a continuous current o1' upon an alternating current, or uponhigh frequencyY radiated waves, either damped or undamped. b

. Our presentinvention relates particularly to the apparatus used for the reception 'of the signals referred to. We utilize for this purpose two receiving circuits, one adapted to receive dots and the other to receive dashes. These circuits are so. organized that one of them alone becomes operative when a signal ofone kind, for instance a dot, is received, while when a `different signal, for instance, a dash, is received, both circuits become operative. This selective action of the receiving circuits may be effected in a variety of ways. For example, they may bev of dlii'erent orders of sensitiveness, whereby the dash circuit will be unresponsive to the weaker dot signals, whereas` both circuits will be responsive to the stronger dash signals. Instead, the two receiving circuits may be ot'equal sensitiveness but be Vso related'to the incoming signals that the dot circuit will absorb greater energy than the dash circuit, whereby the former will be operated 'by the relatively weak signals representing dots, while both circuits will be operated by the 'relatively strong signals representing dashes. This variation in energy absorption of the two circuits can be accomplished by either coupling the two cir# cuits directly to the line in such a way that the potentials applied to the respective circuits are different, to thussecure the reime quired selection, or instead the two circuits may be inductively or otherwise coupled to the line to secure the same result.

We preferably employ in each of the selective receiving circuitsan audion detector by means or'1 which the received signals Will be detected as currentvariat'ions in the output circuit thereof and by means of suitable vacuum tube amplifiers-coupled to the respective detectors .the signals thus received make use of a special type of highly sensi tive relay described in a paper by F. W, Dunmore in the Journal of the American Institute of Electrical Engineers, for April,

1922, said relay employing' a vacuum tbe whose grid is biased by anegative potential io suitable printer.`

" ltrol relay will whereby. normally current. flows in the plate' circuit.; The relay corresponding to the selectivereceiving circuit responsive to signals 'of lowlramplitude, for instance dots, controls a localcircuit in which is included a differential relay which in. turn controls a localcircuit, including the coil of a suitable, indicatoror recorder. This may be'any devicel for indicating or recording-the signals, suchfor exampleas fasiphon recorder or a.

The relay which is asso.-

ciated with the other selective receiving circuit is adapted to close alocal circuit in '"iwhich is located a simpleycontrol relay as local p ycircuits recorder.. The respective whichfthus energize the recorder or indicator coil will include adjustable electroinotive, forces or variable resistances, or both,

to vary the currents sent-through theref corderor indicator, whereby the' response vof the recorder or indicator coil to the dotsand dashes may be of the proper ratio rto effec"- tively distinguish the signals.- n

In orderthat our invention may be better understood, attention is directed tothe accompanying drawing forming apart of` this specification, and. in which:

Fi l 'represents'a diagram showing a lsuita le circuit arrangement for carrying our invention' into effect in connection with cable or line telegraphy, the' selective circuits being directly connected tothe line by aresistance or in uctance to secure the desired volt age drop in the respective circuits; andY and'their various instrumentalities maybe of Fig. 2, ardiagrani Vshowing a wireless ref ceiving antenna, the'selective circuits being inductively coupled thereto,.thus permitting the desired differences in energy absorption" to be secured whereby the receiving circuits equal sensitiveness.

In Fig. '1 the line is illustrated as a cable- 1; submarinecr otherwise, but itA will be understood that this may be u an ordinary *l land wire or a receiving antenna 2 as in Fig.

A2. At the receiving station the circuit includes an element 3 which' maybe leither a non-inductive resistance or an inductancer y coil, the line beinggrounded at 4;; .Connectj ed to the resistance or inductance Sfaretwo @selective circuits fand 6, the vformer*receiving dots andthe latter dashes. As shown, the connection is such as to secure a voltage drop across the connections of the-two selective circuits whereby voltage changes due to the signals will be impressed upon the grids otdetectorsj?` and 8, respectively..These'decircuits ina A close a second local 'circuitv includingthesanie coilv of vthe indicator orl battery 19,` and we illustrate a inilliamiileter tectors -are vkofthe ordinary three electrode 5 type. .The-tvv@selectivecircuits 5 and 6 are so coordinatedv with the lineas toberesponf sive to the changes'in amplitude distinguishing the. signals. In Iligfjlfitis assumed that the circuit 5 is more 'sensitive than the circuit c' 6, whereby the formefriwll respond to the,

currents of lower ain litude representing dots, whiletheiatter wi l respondgonlyto 'the currents Y. of larger amplitude; representing dashes.

The relative'- sensitiveness no 'ff the-lcir'ci'iits.,

can be adjusted in any siitableway. 'In Fig..

2, theselective circuits arel illus't-ratedlas be` ing coupled inductively totheinductanc'e coil .3', the desired selectivity of `the circuits being V 1 adjusted by varying the coupling. inthe usual Way. With the Aarrangement-of 2, both` I i be qty-equal S'e'nSiti'VeneSs, the?"- coupling o the'circuit 5 being adjusted so that this cireuit'fwill absorbvv-greaterffenergy from the lineth'an the circuit 6.- In Fig.' l.

itwill be possible to4 provide .for a -larger potential. drop across fthe Aterminals 4of- Athe circuit 5 so as to make thistircuit more're sponsive than the circuitfandfin' this casca f A also both the lselective circutsgrnay be ofv equal sensitiveness.

i The Aoutput circuits 'Q and, 10" 4ofthe de@ i tectors 7 and8, respectively, are connected with suitable ampliiiers-.ll and 12' riespecv tivel ,ioffthethermionic type.- Anyl desired 1' num er o f stages of such a'linplifiers may be u sed to raisethe incoming signals to the desired value. j Associated with .the circuits 5 and 6 are relays 13 and 14e-*respectively which are preferably `Dunmore relays,l above re'- ferred to. We donot illustrate the details of these relays but show only lthe actuating coils 15 and 16 thereof. By using audion'detectors and thermionic yamplifiers and Dun- .more relayswe' find that a very satisfactoryy responseatthe coils 15 land 16 can be secured The 'contacts of the relay 13'- -15 control a vlocal circuit including'the coil 17 of adifferential relay 18.. In this localcircuit is' a when the received signalsv are extremely 2O inthis circuit, although of coursetliis elenient maybe omitted. lThe local circuit-also includes' an adjustable resistance 21vhy which l ably controlled. v v i g The contactslof the' relay lflf-l'conti'ol a local. circuit in which lis located a-battery vthe current in the local circuit may be suit-l 22,a control-relay 23, and a coilv 2 4 on vthe cludes a variable resistance 25 by means vof 'which the current therein 'may be properly controlled. A milliamrne'ter26 iS. also shown in this circuit. l v The differential relaylS controls contacts- 'in a local circuit 27 .including a battery 28 diiterential--relay opposing they eifectof the coil-17 tliereon. This local circuit also inc understood thatthe local circuit of the'coil ceived to be a.. dot represented .of smaller amplitude, this will be selected by the receiving .circuit 5, the other selective circuit 6 being unresponsive thereto by reason of its inferior sensitiveness or otherwise as above explained. The voltage change in.

the circuit due tothe signal received will be impressed upon the 'grid'of the detector 7 resulting in a current iow in the output circuit 9, which by means of' the amplifiers 11, will be raised to the proper valuev to actuate the coil l5 ofthe relay 13. This-will close `the Contact of the local circuit including thecoil 17 of the"diii`erential relay land will. result in closing the local ciicuit 27 of the indicating orrecording device, giving a re` sponse therein corresponding to the dot, this being determined by properly adjusting the local circuit 27. 4In case a-dash signal is'l received the energy will be sutiicient to operate the detector 8 of the selective circuit 6, causing the relay coill 16 to be energized and closing the local circuit to the controlrelay, 23. l The energy of the vdash signal will also be detected at the detector 7 and will result in the operation of the relay .coil 15, but since the two differential coils 17 and 24 on the differential relay oppose each other the closing of the relay circuit when a dash sig-V nal is received will neutralize the current in the vcoil 17 due to the operation of the relay magnet and hence the differential relay will not/betoperative. It will, of course, be

justed .f'o as to secure at the indicating orv Vrecordingr device any differences desired in the response to the dots and dashes ot' the signal; that is to say, while the signals themupjveg may diier from each other by coniparatively small amounts, theI reponse at the indicating and recording device may he several times as large for one as for the other.

'prising in combination selective circuitsin which the respective signals are received, separate relaysoperated by the respective signals, one corresponding tothe dots and vthe other to the dashes, and a common receiving device controlled bysaid relays giving an indication dependentupon the signal received, substantially as set forth.

-2i Apparatus for receiving telegraphic signals Where the 4dots are distinguished from thedashes by variations in amplitude, comprising in combination selective circuits for receiving the respective signals, means for amplifying thereceived signals, separate relays operated by the amplified signals, one corresponding to the dotsand the otherr to the dashes, anda common receiving device controlled by said, relays giving an indica-r action of both selective circuits whereby a different indication. will be secured, .substantially as set'forth.` 3,

4. Apparatus for receiving telegraphic signals where the dots are distinguished from the dashes by variations in amplitude, comprising in combination a yselective .re-

ceiving circuit operated by the signals of `ing device being also operated by the joint lower amplitude, a differential lrelay controlled therefrom. an indicating device controlled from said differential relay to give an indication therein corresponding to, the

signals of lower amplitude,v a second selec vtive circuit operated by the signals of larger amplitude, which signals also operate the y first selective circuit, a relay controlled from the second sclective circuit and neuoperated by the signals of lower v'means for amplifyingsaid signals, an 'indieatin-g device'contro'lled by the li'iinpliied :"sigr'ials givean vindication corresponding g-.where-.tlie dots are .distinguishedqfrom the dashesby differencesin amplitude, a' line, twoselective circuits associated therewith, a Y g ing the'first 'selective nircuit, means for relay for, each vselective circuit, a differential v`p'lifyin'g the' signals'in the second select iv ;v circuit, enf-indicating device controlled',"by the latter amplified signals v to give an' indi? o he "Signel'of lower amplitude, a: secoue selective ircuit'operated by the' currents 'of largerfarnplitude, said currents also operatcation'fj-corresponding' theretol` -"and .means .whereby the amplified signals in' the Second selective circuit neutralize vthe effect on the indicator.. 'o f`thesignals of the first selective circuit, substantially" as set forth. f i i6'.y A p'aratus for receiving telegraphic sigl-nalsw ere the dots are distinguished from theda'shesbyvariations in amplitude, com" prising in combination a selective .circuit operatedly the signals of lower amplitude,

an-'indicatingldevice controlled by said signals Vtfgive'an indication corresponding to. the' saine, a second selective circuit operated ze by the signals oflarger' amplitude, said signals also operatingthefirst selective circuit,

.means whereby vthe signals of larger amplij'tude control the indicating device to givey an indication-therein correspondingt-o said signale, and means whereby the signals of the "sec'ondselective circuit neutralize the=effect` ofthe signals' in the'rst vselective circuit on "thefindica'tin'g device, .subs ta ntially'as sety v Tf-*An apparatus for receiving signals wherejthefdots 'aredistinguished from the 'dashes by"differences in amplitude,a receiv.-

ing circuitf'two selective' vcircuits associate l` 'therewith,v.one 'selecting the signals of lower amplitude and the other the signalsof larger amplitude, and means whereby a'coinmon iii-1.1

`v dicatingdeviceis controlled, from the two selectivecircuits'to give an indication. corresponding to the respective signals, substam 8.' An apparatus fori receiving signals where the dots arci-distinguished from .the

"dashes by differences vin amplitude, a receivingcircuit, two selective circuits associatedl therewitliv-'for receiving thel respective sigf nais, 'means' for.y amplifying thesignals re ceived in the respective-selective circu1ts,and

means .whereby tl'ie' amplified signalsmay control a -coin'nion indicating device to give indications thereincorre'sponding to the respective signals, sibstantially-as set forth.;

9. An* apparatus ior receiving signals l where"the dots'are distinguished fromthe dashes bydifferencesi'namplitude, aline, two selective circuits associated with, the

- line` for receiving tlieA respective j signals, a relay for each` selectivecircuit, and means wherebysaid relays'wi'llL-'control a common" lforth. v

indicating device tofgi've an' indigzg'it'ion` cor: lresponding to the respective s1gnals', subst an tially as set forth.

10. An' apparatus for receiving signals relay.. controlled by one of said relays, a sim- -pl'e relaycontrolledbythe relay in the other selective circuit, means whereby the effect of the differential relay is neutralized` when the second selective circuit is operated, 4a-.nd a 'common indicating device under the control of the differential and simple relays for gv ing indications vcorresponding'rto the respective signals, substantially as set :Eorths` 11. Anv apparatus for receiving signals where' the dots are distinguished from the dashes'by differences" in amplitude, a line,

two selectivecircuits,associated with said "line whereby ,the fsignals of lower amplitude whereby the signals, in the second selective circuit 'will neutralize the effect on the indicating'device ofthe signals in the first selective circuit, substantially as set forth.

12. Anapparatus -or receivingfsignals where the dots are distinguished from the dashesfby differences in ampli'tude,a line, V`Jtwo selective circuits associated therewith. 'for receiving the 'respective`signals,l aidetecto-r in each'"selectivecircuit, and means wherebythe; detected signals in the two `selective fci'rcuitswill control a common indieating device togive indicationscorresponding to the respective signals, substantially as set 'orth 1 13. An apparatus for receiving signals i Y vs'fhere-the dots are distinguished from the dashes by .differences 4in amplitude, aline, 'two selective receiving' -circuits associated with said line, an audion detector in each selective circuit whereby an amplified plate current corresponding to the respective sig-v j nals will be produced in each circuit, and,

means whereby theplate currents; of the two detectors Willv control a common indicating device to give indications corresponding to, 'the respective signals, substantially as set This specification signed by GEORGE O. SQUIER and LoUIsfoHEN this 13th day ot' December, 1923, and by JosnPrrO, MAU- BORGNE this .14th day 'of December, 1923.

GEORGE O. SQUIER.

'LOUIS' COHEN;

JOSEPH vo'. MAUBonG-NE." i 

